Preoperative Pain Threshold and Rapid Recover Programs

A minimum of 200 patients, 100 hip and 100 knee arthroplasty participants, will be recruited for this study. Preoperatively, patient pain threshold will be recorded both objectively (Pressure algometer) and subjectively (brief pain inventory). In terms of location, objectively this will be tested during the preoperative visit in clinic by the approved, trained research staff, as well as the subjective brief pain inventory.

Objective pain measure: Pressure algometer will be obtained in the standard fashion as follows: the probe is applied at a 90 degree angle to the skin at a constant rate of 10kPa/s to minimize the impact of the examiner's reaction time on recorded pain thresholds. The participant is instructed by the measurer to say "stop" when the sensation of pressure became the very first sensation of pain. There will be three spots to test patients, one for familiarity of the testing and the other 2 for data collection.

• This is initially performed once on ipsilateral the tibialis anterior as a "warm up."
• Then 3 measurements are taken on the operative medial epicondyle (for TKA) or ipsilateral lateral iliac crest (for THA) and averaged for the official score.
• Lastly, three measurements are also taken on the contralateral olecranon to measure systemic pain sensitivity. If the contralateral elbow has had prior surgery or active bursitis, the ipsilateral elbow will be used. Of important note, the algometer has a max force lock out of 100N to prevent any harm to the patient.
• Dominant Hand Grip strength measured by the average of 3 attempts on a Dynamometer.

Subjectively, the brief pain inventory is a validated pain outcome measure which will be filled out by the participant during their preoperative clinic visit.

Postoperative, the study team will ask the participant at the 6 week mark:

• How many and what kind of opiates did the participant require?
• How many days did the participant require opiates?
• Did the participant require a refill? a. If so, did the participant have this filled in clinic preemptively or place a phone call to the office?

Inclusion criteria

• any participant undergoing elective primary total knee arthroplasty or total hip arthroplasty
• Participants of the following investigators will be approached: Bolognesi, Wellman, Attarian, and Seyler

Exclusion criteria

• previous hip or knee surgery in the operative joint